Miniature Ponies: What’s Inside a Model Engine

How many machinists does it take to build a 10hp engine the size of a pumpkin? No, it’s not the start to a joke—it’s the story of the Black Widow 1⁄3-scale model V8. If you’re wondering exactly how one-third of an engine measures up, pull out your calipers now. A complete Black Widow V8 is 15 inches long from fan to flywheel, 71⁄2 inches across head to head, and 12 inches tall from oil pan to blower. We had to stop ourselves from pinching its cheeks, the little cutie.

1/2015in. x 14 in.

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The Black Widow is a Chevy-based, gas-burning model engine built by Ken Hurst and Dwight Giles of the Bay Area Engine Modelers (BAEM)club in northern California. Like its fullsize brethren, a scale-model engine is the result of designs and redesigns as each new builder adds his touch to the process. The Black Widow started as a series of patterns by machinist John Vlalvianos, who was dissatisfied with other model V8 casting kits in circulation. John made some initial castings but passed away before completing a full engine. Fellow BAEM club members Ken and Dwight rescued the patterns and added a supercharger. Ken and Dwight offer casting sets of the Black Widow, but don’t think that means you can just buy one, insert Tab A into Tab B, and fire it up. As it says on the BAEM website, “Unfortunately, it isn’t a simple matter to machine a functioning internal-combustion engine.”

3/20The casting set comes with heads, but Jim had his own made from billet aluminum. Each head has stainless-steel, 1-inch-long valves, custom-machined valve retainers, and roller rocker arms.

Yeah, that’s a bit of an understatement. We spoke with Ken, Dwight, and more recent model-engine enthusiast Jim Kipp about what it takes to get one of these little mills up and running. Jim has a collection of model engines, and he’s currently working on assembling several Black Widows with changes and redesigns of his own. He invited us to his shop to see exactly what’s inside a miniature engine. The answer is, everything that’s inside a big one, only smaller. As for how many machinists it takes to build one? It appears to be an ever-expanding number best described by the equation V8/3 = (M+B) x I. That’s 1⁄3-scale V8 equals machinist plus billet times innovation.

Scaled-down engines are nothing new. Modeler Paul Knapp says he has one from 1919 in his collection, and we’ve seen even earlier references to models of hit-and-miss engines (which only have a power stroke every few cycles to limit rpm, usually for agricultural needs). The BAEM club encourages all forms of model-engine building, and if you think you’re up for the challenge, see BAEMclub.com to find out how to get started on a miniature engine of your own. There’s also an online magazine, ModelEngineBuilder.com.

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Jim had all the supercharger parts made and has been experimenting with different finishes to get a vintage magnesium look, but the blower isn’t just for show. It makes ¾ of a pound of boost. Dwight mentioned that during initial testing on a drill press, Ken Hurst placed his hand on the intake and gave himself a blood blister from the suction.

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See the Video!

Models are nifty when static, but when you fire up 6.28 angry, boosted cubic inches and wing ’em through open headers, that’s unmatched merriment. Experience it by searching “V8 Black Widow” at Videos.HOTROD.com.

1:1 Smallies

Thinking of tiny engines got us to wondering about the smallest-displacement production V8s for American cars. Here’s what we came up with for the tiniest gas V8s from each manufacturer, in order from smallest to largest.

Ford: 136 ci for the little V8-60, ’37–’40

Buick, Oldsmobile, and Pontiac: 215 ci from ’61–’63 (the Olds engine was used in the Pontiac; the smallest Pontiac-designed V8 was the ’78–’81 265-incher)

Mercury: 221 ci, the first Windsor, introduced in 1962

Studebaker: 224 ci in ’55–’56

Dodge and Plymouth: 241 ci, available as a Hemi for the Dodge and only in a poly-headed version for Plymouth in ’53

Nash, Hudson, and Rambler: 250 ci, from ’56–’61

Cadillac: 250 250ci, the turdly HT-4100 from ’82–’85

Chevy: 262 ci 262 ci in ’75–’76, even smaller than the 265ci first small-block in ’55